Doctor for calendering machines



Oct. 4, 1932. H. w. MASON DOCTOR FOR CALENDERING MACHINES Filed Sept.29, 1930 2 sheets-sheet 1 Elven/1'02:

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Oct. 4, 1932. H. w. MASON 1,880,455

DOCTOR FOR CALENDERING MACHINES Filed Sept. 29, 1930 2 sheetss heet 2 sW A 0 T 1:

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Patented Oct. 4, 1932 PATENT OFFICE .HERBER'I. WARREN .MASON, OFWILMINGTON, DELAWARE DOCTOR FOR CALENDERING MACHINES Application filedSeptember 29, 1930. Serial No. 485,244.

The inventionirel-ates to paper making machinery and more particularlyto calenders of the vertical roll stack type where there are a series ofdoctors.

The object and reason for this invention is to provide a simple,cheaper, and more easilyoperated and adjusted device for guidingpaperthrough the calender rolls and for cleansing the rolls withoutdamaging them.

One ofthe features of the invention is the provision. of adjustabledoctor means readily applicable to an existing housing or frame wherethere have been aprevious set of doctors of an unsatisfactory'type. Theentire adjustable doctor mechanism is so simple of construction'that anymachine shop with the material on hand can readily construct thecomplete set and install same in a calendering machine with their usualtoolsand me chanical force.

Another feature is the provision of means for adjusting the cleaningdoctor horizontally and vertically into desired engagement with theindividual calendaring rolls and the ease of adjustment, simplicity andefficiency of the tension catch.

The ease of operation, manufacture and in.- stallation and adjustmentcan m-oreread ily be comprehended by referring to the followingdescription in connection with the accompanying drawings.

- Figure 1 isa-sectionalside elevation of the calender stack showing thedoctors in their contacting position with their individual rolls. At theleft the :entiredoctor supporting system is shown mounted on the housingor calender frame and supporting each and all of the doctors on one sideof the stack, whereas the doctors areshown unsupported anddiagrannnaticany but in their engaged position with the rollsattherig'htzof this-figure.

is an emerged "partly sectional view of the doctor Iblade mounting whichis shown in front elevation in Fig. 3. v

Fig. 2a is a detail of the doctor trunnion. bearing.

Fig. "3is-a plan view of the doctor bladeand support.

Fig. i is a partial plan view o'fzthe construction of Fig. 2.

Fig. 5 is an elevation on line A-Aof Fig. 2, showing the doctor arm Gand the adjustable catch M.

Fig. 6 shows a Vertical section through the assembled mounting on lineBB of Fig. 2.

Fig. 7 is a horizontal section of the mount clamp.

To facilitate the comprehension of "the drawings let it be said that-Zrepresents a calender stack housing or frame containing a stack of rollsX. The following nomenclature will then pertain to this invention.

A. Doctor blade. B. Doctor angle. C. Doctor blade retainer. D. Doctortrunnion. G. Doctor arm. H. Doctor arm pivot. J. Adjustable mount. J1.Bearing for doctor trunnion.

pins). J2. Upper adjustable pin. J3. Screw for adjustable pin. K. "Catchclamp. L. Catchcla-mp bolt. M. Adjustable catch bracket. M1. Adjustablecatch ordetent. N. Adjustable mount clamp assembly.

(a) Mount slide. .(b) Vertical adjustment clam-p.

(0) Vertical adjustment clamp bolt. (d) Mount retainer. 6) Mountretainer bolt. 5;) Mount lock set screw.

9) Mount guide. (71,) Mount guide 0. Support. P. Support bolt. Pl.Support bolt nuts.

(Lower bolt (rivet) Referring to the sectional view, Fig. '6,

the support 0 is mounted on the frame .or housing Z by means of thesupport bolt P (which may be either a turned bolt with a shoulderat eachend, or a threaded rod passing through a short section of pipe) and twonuts P-l which fasten the support bolt in the housing and secure thesup-port 0 thereby to the housing.

I The support 0 consists of a flat barof structural steel, the length ofwhich'is governed by the height of the calender stack. This supportcontains holes to receive support bolts P at convenient intervalsthrough out its length and if there should be any interference with theadjustable mount clamp assembly N the support bolt P is relocated in thefield by drilling two holes, one in the support 0 and one opposite inthe housing Z.

Now referring to Figs. 2 and 3, a thin metallic web doctor blade A issecurely but yieldably and'flexibly fastened to the doctor angle B bymeans of blade retainers C.

Blade retainers C are yieldably held on doctor angle B by spring clampsR. The spring clamps are mounted on the angle B and comprise hooked lugsB1 receiving leaf springs R the ends of which bear upon the surface ofthe blade retainers. The blade retainers can swing slightly in eitherdirection about longitudinal axes against the act-ion of the yieldablesprings B.

Each blade retainer comprises a stri of metal having a blade receivinggroove at one edge thereof, and a rod T spring pressed to normally closethe mouth of the groove and to bear upon the blade when it is insertedin the groove. Springs U are provided fixed to the retainer C andbearing down upon the rod T to urge it into engagement with the extendedportion of the retainer C.

Hooked bracket members V are preferably provided secured to the retainerand engaging the spring pressed rod to hold it against displacementlaterally while permitting limited movement against the action ofsprings U.

The grooved blade retainer C may be made in one piece but preferablycomprises fiat strip C-l to which is secured superposed strips (1-2 and0-3 by rivets or screws (1- 1.

A structure is thus provided whereby the blade may be manuallv insertedand re moved from the retainer by a simple movement, one end of theblade being pushed between the spring pressed rod and strip and into thegroove S and the whole edge of the blade then readily follows. The bladeis then secure in its retainer, while readily removable and slightlyflexible or yieldable in the retainer when pressed against the roll, andthe retainer itself is yieldably mounted on the angle B. i

The doctor trunnion E, shown in Figs. 2 and 3, is designed to fit thedoctor trunnion bearing J -1 and is securely fastened to the doctorangle B by means of screws or rivets F. The doctor angle B is alsoequipped with a doctor arm @r which is held in position free to rotateabout the doctor arm pivot screw H secured in a tapped hole in thedoctor trunnion E.

The adjustable mount J supports the adjustable catch M by means of thecatch clamp K secured by the catch clamp bolts L. This nast estadjustable mount J, by releasing the mount lock set screw f shown inFigs. 2 and 6, is free to slide in a horizontal direction either towardor away from the roll X and is entirely supported by the adjustablemount clamp assembly N shown in section in Fig. 7 It is seen byreferring to Figs. 2 and 6 that this adjustable mount clamp assemblyconsists of a mount guide 9 riveted by means of mount guide rivets h tothe mount retainer (Z. The mount retainer (Z is equipped with a mountlock set screw 7 and in turn is secured to the mount slide a. The mountslide a has two holes through which the vertical adjustment clamp bolts0 pass and engage their threads in threaded holes in the verticaladjustment clamp Z). By loosening the vertical adjustment clamp bolts 0it is seen that the entire adjustable mount clamp assembly N togetherwith the adjustable mount J and consequently the entire doctor, are freeto be moved vertically up or down the support 0. This mount J and itsclamp assembly N when in the desired position is secured by simplytightening the vertical adjustment clamp bolts 0 and the adjustablemount J becomes fixed in a vertical position but is free to movehorizontally.

When the proper horizontal adjustment is attained the adjustable mount Jis fastened by tightening the mount lock set screw f, and thus thedoctor blade and its supporting structure is supported by the doctortrunnion E in a fixed position horizontally and vertically but remainsfree to rotate about this trunnion in the bearing J -1 for the doctortrunnion in the mount J.

The bearing J -1 for the doctor trunnion comprises three pins, two ofwhich, forming a'cradle, are fixed. in mount J and the third or upperpin J -2 being adjustably clamped to themount J by means of screws J -3.The upper pin J 2 is provided with a depending forked portion whereby itmay receive the screw J -3 and be adjusted relative to the mount whenthe screw is loosened. The bearing J -1 is thus capable of receivingdoctor trunnions E of difierent sizes.

In inserting or removing a doctor unit comprising blade, retainer,angle, and trunnion, the pins J -2 are simply loosened and removed orswung sideways to permit the doctor unit to be dropped into place orremoved with great ease.

Now the catch clamp bolts L having been loosened, the doctor arm G isswung about the doctor arm pivot H until it is engaged beneath theadjustable catch or detent M of bracket M-l.

The adjustable catch bracket M-l is-then moved towards the catch clamp Kuntil the proper tension is imparted to the doctor blade A contactingwith the roll X, at which point the adjustable catch bracket M-l isfirmly locked by tightening the catch clamp bolts L.

its

It is seen that by-exerting a slight pressure on the doctorarm G androtating or swinging it about the doctor arm-pivot H; the

, arm G becomes disengaged from the adjustable catch M and the entiredoctor is free to rotate about the doctor trunnion and the previousadjustment is immediately obtained byreversing the operation and againengaging the doctor arm G beneath the adjustable catch M; or that atighter adjustment may be obtained by loosening the catch clamp bolts Land further advancing the ad justable catch bracket hi toward the catchclamp K and againtightening the bolts L. The catch or detent M ispivotal-1y mounted tothe bracket M as shown at W. p The catch has ashoulder Y to receive the arm G which may be provided with a lockingstud m.

The catch M extends beyond the bracket M and its end is secured to anoperating member or cable 8 which connects all of the catchesM of thesuccessive mounts together sothatthey are operatedin unison by thecable. g After the arm G is swung beneath the catch hi which may exertinitial tension on the blade inengagement with the roll, depending onthe position of bracket M the tension may be further regulated(increased or decreased) according to the positions in which the cableis retained.

The individual doctors while individually releasable and regulated as totension by bracket M areal-so operable in unison by chain or cable '8 tofurther adjust tension or to-release the doctors from the catches. Thedoctor arm may be under initial tension upon being swung beneath thedetent with the cable elev-atedyso that release could not beaccomplished by the cab-lealone but after operation of the cabletorelease the doctor arms as far as possible, the doctor arms must beindividually pushed down to release them from the catch. This is amatter of adjustnient of the catch bracket in the mount which of coursecould be adjusted so that there would be no initial tension uponswinging the doctor arm beneath the de'tentand all the tension would beapplied by the cable which when released would also rel-case the doctorarms.

It ispr'eferred to adjust the catch bracket so that the latched doctorarms are under tension initially, supplementary tension being applied bymeans of the cables.

cables is urged upwardly by sprirug' '6 'se-' cured to the frameand isretained in adjusted depressed position by a suitable latoh means suchas toothed quadrant and. dog means shown'at v in connection with cableoperatingmember 'w.

A similar cable (not shown) is used in connection with the opposite setof doctors which are indicated only diagrammatically "BE in Fig. 1 "bythe location of their trunnions.

The cables are preferably located at the same-end of the machine.

Only the upper and lower doctors of' the left hand set in Fig.1 areshown, as the r emaining doctors are of substantially the sameconstruction and dimensions, all of the doctor arms being connected toand operable by the cable 8.

Inthe event of the doctor blade A'beco'ming'worn out the doctor isdisengaged by releasing'thedoctor arm G from the adjust able catch M andthe doctor assembly is rotated about the doctor trunnion E-untilthedoctor blade is readily accessible. The doctor blade A is then removedby simply pulls ing it out and a new one is simply inserted. The reneweddoctor is then ready for service. Should any "further adjustment berequired in either a vertical or horizontal di rectionsuch adjustmentmay quickly be obtained as before'des'cribed.

With this form of doctor on narrow trim machines it will only benecessary to have the doctor arm G and its associated parts at one endof thedoctor but where as oh wider machines, the doctor angle B cannottransmit suiiicient'torque to properly engage the doctor blade A withits co-acting roll X at the far end of the doctor, two arms may beinstalled, one at each end.

I claim I 1. A doctor mounting for calenderingzmachines including asupport adjacent theirolls, a doctor blade adapted to engage 'a roll, ablade carrying member pivotally mounted in said support for swingingsaid blade toward or away from said roll, said blade carrying membercomprising an angle bar and a blade retainer bar, and spring clampsyieldably lfiolding said blade retainer bar t'o'said angle '2. A doctormounting'according to claiml in which said spring clamps comprise hookedlugs on the angle bar, leaf springsbeneath said hooked lugs, the ends ofsaid leaf springs bearin upon the surface of the blade retainer ar. 7

3. A doctor mounting according to claim 1 in which said blade retainerbar comprises a 'strip' of metal having a blade receiving groove at oneedge thereof and a rod mounted adjacent the mouth of the groove, springsfixed to the retainer bar and engaging-said rod to urge it into positionto normally close the mouth of the groove and to bear upon the bladewhen it is inserted in the groove.

4. A doctor mounting according to claim 1 in which said blade retainerbar has a blade recelving surface at the outer side thereof,

spring means fixed to the retainer bar and overlying said bladereceiving surface,and a rod beneath said spring means and yieldablypressed thereby into engagement with said blade receiving surface.

5. .A doctor mountingaccording to claim 1 in which said blade retainerbar comprises a base strip of metal, to which is secured a pair ofsuperposed strips, said superposed strips forming a blade receivinggroove with said base strip, said base strip being extended beyond themouth of the groove, a rod extending along the mouth of the groovebrackets loosely engaging said rod to hold it adjacent the mouth of thegroove, springs on said superposed strips engaging said rod andyieldably holding it against the extended portion of the base strip toprovide a spring clamp for the blade.

6. A doctor mounting for calendering machines including a supportadjacent the rolls, a clamp adjustable along said support, a mountadjustable in said clamps transversely of the support and toward or awayfrom a roll, a blade carrying member pivotally mounted in said supportfor swinging the blade toward or away from the roll, said doctor bladecarrying member having trunnions at its ends, bearings for thetrunnions, each including three pins, two of said pins being fixed insaid mount and forming a cradle for said trunnion, and a third pinadjustably and removably mounted above the other two.

7. A doctor mounting according to claim 6 in which said third pin isprovided with a slotted bracket portion, a screw in said mount, saidslotted bracket portion being adapted to be adjustably clamped to saidmount by said screw.

8. In a calendering machine, and in combination, a roll, a supportdisposed alongside the roll and extending at right angles to the axis ofthe roll, a clamp adjustable along said support, a mount adjustable insaid clamp transversely of the support and toward or away from saidroll, a. doctor blade adapted to engage said roll, a blade carryingmember pivotally mounted in said support for sw1nging said blade towardor away from said roll, an adjustable detent on said mount and an armpivoted to said pivoted blade carrying member and adapted to be swunginto position beneath said detent to position the blade in engagementwith said roll under tension determined by the adjustment of saiddetent.

9. Apparatus according to claim Sin which the axis of the pivotalconnectionof said arm to the blade carrying member is substantiallytransverse to the axis of the pivotal connection of the blade carryingmember of said mount. 1

10. Apparatus according to claim 8 in which said adjustable detentcomprises a bar member having an overturned end and movably supported onsaid mount by means of a clampbar secured to said mount by clamp boltsor the like.

11. Apparatus according to claim 8 in which said adjustable detentincludes a deassess;

tent bracket on said mount, a detent member pivoted to the bracket andadapted to be swung up or down, a cable connected to the free end ofsaid detent member for moving it up or down to adjust the tension onsaid arm and blade.

12. Apparatus according to claim 8 in which there is a stack of rolls,and a plurality of doctor blades and mountings, there being a doctorblade andmounting for each roll, each of said adjustable detentsincluding a detent bracket on said mount, a detent member pivoted to thebracket and adapted to be swung up or down, a cable connected in commonto the free ends of all of said detent members to move them up or downin unison to adjust the tension on said blades in unison, means forretaining said cable in adjusted positions, and spring means urging saidcable to relieve the tension.

13. Apparatus according to claim 8 in which said adjustable detentcomprises a bar member having an overturned end and movably supported onsaid mount by means of a clamp bar secured to said mount by clamp boltsor the like, said detent bracket being movably supported on said mountby means of a clamp bar secured to said mount by clamp bolts or the likewhereby the blades are independently adjustable as to tension,adjustable in unison by said cable, and independently releasable fromsaid detents.

h. In combination in a calendering machine, a vertical stack of rolls avertical support beside said stack, and a doctor blade assembly for eachroll including a clamp adjustable vertically along said support, a mountadjustable horizontallyin said clamp transversely'of the support andtoward or away from said roll, a doctor blade, a blade carrying memberpivotally mounted in said mount for swinging said'blade about ahorizontal axis into. engagement with said roll, an adjustable detentmovable on said mount to determine the pivotal position of said bladecarrying member, and an arm pivoted to said pivoted blade carryingmember and adapted to be swung into position beneath said detent toposition the blade in engagement with said roll under a tensiondetermined by the adjusted position of said detent.

'15. Apparatus according to claim 14 in which the axis of said pivotalconnection of the arm to the blade carrying member is substantially atright angles to the axis of the pivotal connection of the blade-carryingmember to the mount, said adjustable mount clamp including portionsengaging opposite sides'of said support with clamp bolts extendingtherebetween, said mount clamp proprising a bar member having anoverturned upper end and movably supported on said mount by means of aclamp bar secured to said mount by clamp bolts or the like, said bladecarrying member comprising an angle iron having secured thereto atrunnion for pivotal engagement in said mount, and said blade beingremovably mounted in said carrying member by means of a blade retainerand springs.

In testimony whereof, I afiix my signature.

HERBERT WVARREN MASON.

